If self-driving cars are as useful as their boosters say, everybody will want one—every family, every car company and city trying to build a municipal fleet, and every retailer trying to put their business on the cheapest, most-valuable real estate available: public roads. Without smart urban planning, the result will be infernal congestion, choking every city and requiring local governments to lay ever-more pavement down to service American automania.

There already is infernal congestion and likely an excess of parking relative to productive land use in thickly settled areas: until the Wise Experts show more competence with the existing conditions, perhaps they ought Butt Out of imposing constraints on new technologies.

In sum, self-driving cars have the potential to improve existing transportation technology in unambiguous ways, to expand the suburbs, and to create new economic opportunity for a variety of industries, from hotels to restaurants. But they might also change the character of our cities for the worse and strangle roads with cars in a way that ruins the urban experience for millions of people. What does this sound like? It sounds like the legacy of highways in America.

Yup. Furthermore, on-demand autonomous cars are likely to have surge pricing at levels that make Uber's rush-hour or bar-time tariffs look like Bargain Thursday at a White Sox game.

Autonomous cars aren’t just cars. They’re infrastructure. If the U.S. wants to avoid its past mistakes, American cities have to start thinking about how to use autonomous cars to make their downtown areas more efficient for humans, not just for machines. That could mean aggressive congestion pricing, limiting the number of AVs in an area, prohibiting certain companies from operating such cars, or even capping ownership. Today these may seem like radical steps. But compared to a future where every family and company tries to operate an autonomous car in the same metro area, it may feel like pure old-fashioned conservatism.

The owner of a motor vehicle, even an autonomous one, can treat the insurance and depreciation on the car as a sunk cost, and consider only the out of pocket costs of the next trip, and plan his departure to take into account the expected congestion in front of him. An Uber driver, like the Model T owner offering jitney service in the Woodrow Wilson years, might make a similar calculation: better to get a little bit of eating money out of a car he already has. That would be a good way for the operator of a fleet of autonomous cars for hire to go broke: thus the fleet size, and the surge prices, are likely to reflect the expected travel times and the expected delay costs imposed on later departures by fleet cars making earlier trips. It's unlikely, though, that any entrepreneur has figured all of that pricing out yet, it's something likely to emerge with practice, price discovery, and a few business failures. "There is a future where a handful of efficient, self-driving cars operated by a responsible fleet manager could return American cities to a superior age, where people mixed promiscuously around the streets, rather than be confined to narrow sidewalks to maximize space for cars."

Wishful thinking, dear reader. That handful of self-driving cars will be offering their services at very high rental rates, and the owners of self-driving or drive-yourself cars will be looking for parking spaces and otherwise posing hazards to pedestrians, just as we currently live.